Panasonic DMR-EH55S - setting time

Hold down "channel up" and "channel down" at the same time for a few seconds.

That will reset everything to default and you can then set the time manually.

With the unit ON you will want to hold down the CH up and CH down buttons on the main unit for ~10 seconds(until it shuts off). I believe after it resets you will need to turn the unit back ON and push the TVGOS button at which point it will start the setup. Answer the setup questions and follow the directions. At this point I believe you should be able to manually set the clock. After several days when you push TVGOS(if it could not find a signal) you will be asked if you want the unit to keep searching for a TVGOS signal. Answer NO and your unit should stop searching for TVGOS and allow you to continue setting your clock manually.
Note the EH-55 has the old daylight savings times so you don't want to use auto for DST otherwise your clock will change at the wrong days. You will need to manually spring ahead or fall back at the proper dates.

edit, Rammi beat me to the punch.

If the above instructions don't work, my notes might help--- page 67, center of page just above "Messages", "I do not want to use the TV Guide On Screen system", which refers you to page 64.

Disabling the TVGOS is a bit of an exercise, but fortunately has to happen only once. It doesn't take two days. The clock will drift eventually, but is pretty good.

You've been alerted to the need to manually set for Daylight Saving Time. One other potential "gotcha" is schedule "Daily" is for a 5-day week, M-F. This is documented in the E85H manual but not in the EH55.

Works beautifully, once you get the TVGOS disabled.

And the reset will not affect any of the programs stored on the HDD, right?

Correct, the only thing that would effect them would be a HDD format or delete all